I am travelling around Central Amercia for 2 months, leaving in about 10 days time.

I'm taking the following kit with me:

Canon 60D Tamron f3.5-4.5 10-24mm Canon f4 24-105mm L Sigma f1.4 30mm

I have noticed that when I go to print large photos, some of the dimensions of the photos do not always fit to the proposed print dimensions. Perhaps this is down to me just using cheap online print shops, but I was hoping to get a take on the preferred aspect ratio for a Canon 60D (cropped sensor).

It looks as though the default is 3:2.

I doubt I will ever return to these countries after my trip, so I am hoping to have my settings in place so that I do not regret using my current camera settings when I return home to process and print photos.

The aspect ratio is determined by the sensor dimensions and for DSLRs this is usually 3:2 which probably explains the existence of 6x4 prints. Some other cameras have sensor dimensions which match 5x7.

If you're not sure how large you are going to print while taking the shot I guess framing loosely will allow cropping to any of the standard paper sizes later.

I have taken to printing at A4 size rather than 10x8 as this is closer to 5x7 ratio. 10x8 requires you to leave a heck of a lot of empty space on the long dimension which will be cropped off later.